1. Field of Invention
This application is directed to a paper-like hypertext system that supports reading and browsing. In particular, the invention is directed to the creation of ad-hoc links between user-specified passages in documents using free-form ink annotations.
2. Description of Related Art
People use annotations and notes to organize information. Although annotations and notes serve the same purpose, there are many tradeoffs between marking on the document and marking in a separate place. Notes are concise to review, but take more effort to create. Notes have more context from the reader""s ideas but less context from the document and short annotations are easy to create, but long annotations are awkward because space is limited.
Furthermore, people often organize their annotations and notes explicitly. Some writers use note cards, which can be flexibly sorted into different categories, to help them build connections between topics. Unfortunately, notecards require much effort to use. Information analysts often sort annotated paper into piles and some clip out useful sections with scissors and organize the clippings.
Once people reorganize information on paper, they often lose access to the original material. Notes are easier to work with than annotated documents, unless some information is missing. Similar problems arise with secondary notes and outlines that writers use to organize thoughts. There is a need for a free-form ink system that generates links between documents.
In Marquee, a real-time tool for video logging (Marquee: A Tool For Real-Time Video Logging, Weber et al., In Proceedings of CHI ""94, ACM Press pp. 58-64, (1994) incorporated by reference herein in its entirety), a handwritten word could be circled to copy it to a palette of ink keywords, from which it could be dragged onto other pages. These ink keywords were later converted to text manually in order to support searching. Marquee, however, does not consider the shape of the ink keyword. Furthermore, Marquee""s keywords do not act as links. Therefore, a user cannot select an instance of a keyword to view other instances of that keyword.
Although a later version of Marquee uses ink matching to highlight matching notes, ink matching was neither combined with the keywords nor used to create links (Scribbler: A Tool For Searching Digital Ink, Poon et al. CHI ""95 short paper, (1995), incorporated by reference herein in its entirety). Other systems which have used ink matching have not supported links.
ConMentor supports ad-hoc linking and annotation on the Web. Users of ComMentor can annotate documents with a keyboard and a mouse, and can include them in a set by selecting from a list of sets (Shared Web Annotations As A Platform For Third-Party Value-Added Information Providers: Architecture Protocols, And Usage Examples, Roscheisen et al., Technical Report STAN-CS-TR-97-1582, Stanford Integrated Digital Library Project, Computer Science Department, Stanford University (1995), incorporated by reference herein in its entirety). ComMentor, however, does not support free-form ink.
GO PenPoint includes a pen-based interface for manual linking. A link gesture creates a xe2x80x9cbuttonxe2x80x9d that points to the current page. The button can then be dragged to another page to complete the link (The Power of PenPoint, Carr et al., Addison-Wesley, Inc. (1991), incorporated by reference herein in its entirety). PenPoint supports free-form ink annotation but does not combine it with linking in any way. Co-Assigned U.S. patent application Ser. No. 08/929,426, filed Sep. 15, 1997, and incorporated herein in its entirety, discloses an active reading machine that creates links automatically from ink marks, but users do not have direct control over the target of the link. The system creates margin links and further reading lists that produce links via queries on the text, not ad-hoc links.
Co-assigned U.S. patent application Ser. No. 09/059,204, filed Apr. 14, 1998 and entitled xe2x80x9cMethod and Apparatus for Displaying References to a User""s Document Browsing History within the Context of a New Documentxe2x80x9d, incorporated by reference herein in its entirety. That invention extracts portions from previously read documents and compares those portions to passages in a new document. Those passages in the new document which are identified as being closely related to a portion of a previously read document are provided with a selectable link to the portion in the previously read document.
Another co-assigned U.S. patent application Ser. No. 08/929,427, filed Sep. 15, 1997 and incorporated by reference herein in its entirety, discloses a system that extracts portions of a document that have been annotated with free-form ink and presents the annotation with their surrounding context in a separate view called a reader""s notebook. The reader""s notebook creates a special view with links to annotations, which could be considered a multi-way link. Although users of this system can specify which classes of annotations appear in the view, users cannot include or exclude specific annotations from the set. Furthermore, the links are based on properties that a user explicitly assigns to the ink by selecting a pen, rather than on the shape of the ink.
Yet another co-assigned U.S. patent application Ser. No. 08/821,311, filed on Mar. 20, 1997 and incorporated by reference herein in its entirety, discloses a system called Dynomite. Dynomite uses an ink index that organizes free-form ink notes in the same way that the reader""s notebook organizes annotations (Dynomite: A Dynamically Organized Ink and Audio Notebook, Wilcox et al., In Conference Proceedings of CHI ""97, ACM Press, pp. 186-193 (1997), incorporated by reference herein in its entirety). Dynomite also allows users to assign keywords to pages, and all the notes on the pages with those keywords can be grouped together. However, as with the reader""s notebook, a user cannot include or exclude specific annotations from these groups, and links are based upon properties associated with the ink rather than on the shape of the ink.
Dolphin creates links to new pages from annotations that are marked with a xe2x80x9cboxxe2x80x9d gesture (DOLPHIN: Integrated Meeting Support Across Local and Remote Desktop Environments and Live Boards, Streitz et al., In Proceedings of the Conference on Computer Supported Cooperative Work, pp. 345-358 (1994), incorporated by reference herein in its entirety). These links are hierarchical, not ad-hoc. DOLPHIN does not allow users to specify arbitrary destinations for these links and treats a bookmark as a gesture and removes it after a link has been created.
The active reading machine disclosed in U.S. Patent Application Ser. Nos. 08/929,426, 08/929,427 supports reading and browsing over a wide variety of documents. Many of these documents were designed for presentation on paper and, therefore, lack hypertext links. One way to create a browsing environment is to automatically detect topics, references and other static document structure and then to generate the links automatically (Automatic Hypertext Construction, Allan J., Ph.D. Thesis, Cornell University (1995), incorporated by reference herein in its entirety). Unfortunately, only a small fraction of all possible links are useful to a particular reader at a particular time and deciding on the right links ahead of time, without any knowledge of a reader""s activities, is difficult.
A system that gives readers the tools for constructing links should be more useful than statically generated computer links because they can reflect a reader""s idiosyncratic interests. At the same time, link construction should not interfere with a reader""s primary activity of reading. However, conventional systems do not provide these features.
The invention enhances free-form ink annotating and note taking by creating ad-hoc links from free-form ink. People can use ad-hoc links to connect notes and outline entries to sources, or to group together the important passages on a particular topic.
Linking by inking may have a number of advantages over traditional link construction interfaces. First, ink is personal and idiosyncratic. People can use the flexibility of free-form ink to make anchors meaningful. Second, linking by inking is an extension of current practice. Readers already use ink marks on post-it notes or colored stick-ons and other types of annotations to characterize information efficiently. Third, because linking by inking requires no explicit interaction, people can create links more quickly and easily than with traditional interfaces where people must invoke a command and then browse for the target of the link.
Readers often link documents together for their own particular reasons. One typical practice is to mark places on different pages with the same circled symbol (e.g., the letter xe2x80x9cAxe2x80x9d or numeral xe2x80x9c1xe2x80x9d), thereby creating a logical link between them. The present invention creates xe2x80x9cink anchorsxe2x80x9d to help readers create idiosyncratic many-to-many links with minimal effort. Circling any mark converts that mark into an anchor. In this way, the system of this invention maintains multi-way links between similar ink anchors.
Ink anchors require relatively little effort to create. Readers can create links without selecting from a list, navigating or typing text. Readers merely create and use their own personal marks for the ink anchors.